<p style='text-align: justify;'>Title page and beginning of an introduction of a polemical treatise on the Karaite calendar by Abū Yaʿqūb Joseph b. Abraham al-Baṣīr, entitled Al-Kitāb ʿalā Aṣḥāb al-Iʿtidāl (“Book against the People of the Equinox”). According to the introduction, Joseph b. Abraham al-Baṣīr was moved to dictate this book when he saw that people incorrectly established the date of Passover because they relied on the equinox instead of the state of the barley crop.</p>